About Sika SikaCim

SikaCim is Sika’s long-established liquid integral waterproofing admixture for concrete and mortar, and it remains one of the most widely specified damp-proofing additives on Indian sites. Rather than sitting on top of a slab like a membrane, it is dosed directly into the mix, so the waterproofing is built into the body of the concrete or plaster itself. The product is based on modified ligno-sulphonate, contains no added chloride, and conforms to IS 2645, the Indian Standard for integral cement waterproofing compounds. It arrives as a brown liquid with a density of roughly 1.00 at 25°C and a pH of 6 or above.

What makes SikaCim practical for everyday RCC and plastering work is its dual action. It reduces the amount of water needed for a given workability, and that lower water-cement ratio is what tightens the pore structure and improves watertightness. At the same time it disrupts the capillary channels through which water would otherwise track, and it noticeably cuts mortar rebound during plastering. For contractors that means less material waste, a smoother finish, and a genuinely economical dosage of just 100 grams for every 50 kg bag of cement. It is compatible with all Portland cements, including slag-blended types, which keeps it flexible across mix designs.

The technical insight

The waterproofing works on two fronts, both tied to the ligno-sulphonate chemistry. First, SikaCim is a plasticiser: it disperses cement grains so the same workability can be reached with less water. Because permeability in hardened concrete is governed largely by the water-cement ratio, that reduction directly shrinks the interconnected capillary pores through which water migrates. Second, the admixture disrupts the continuity of those capillary structures as they form, breaking the pathways that let water track through the section. The net effect is a denser, more cohesive matrix rather than a surface film, so the resistance is integral to the concrete and cannot be scratched or worn off. Because the formulation carries no added chloride, it does not introduce the chloride ions that would otherwise accelerate corrosion of embedded reinforcement, which is an important distinction from older chloride-based waterproofing compounds still found in the market.

Where it is used

• Integral waterproofing of flat and sloped RCC roof slabs
• Internal and external cement plaster on residential and commercial walls
• Beams, columns and slabs requiring built-in damp resistance
• Repair and renovation mortars on leakage-prone surfaces
• Water-retaining and basement mortars in substructures
• Screeds and bedding mortars where a denser, less permeable finish is wanted
• General structural concrete needing reduced water permeability
• Rendering coats over masonry exposed to driving rain

Key advantages

• Waterproofs from within the mix, so protection cannot wear off like a surface coat
• Dual action as a water reducer and waterproofer in a single product
• Economical dosage of just 100g per 50kg cement bag (0.2% by weight of cement)
• No added chloride, so it does not contribute chloride-driven corrosion of steel
• Compatible with all Portland cements, including slag cement
• Cuts mortar rebound during plastering, saving material and improving finish
• Improves workability without adding water, reducing shrinkage risk
• Conforms to IS 2645 and supplied in site-friendly pack sizes from 200g to 230kg

Limitations & considerations

• Excess dosage can delay the setting of concrete, so the 0.2% rate must be respected
• It reduces permeability but is not a substitute for a membrane on permanently submerged or hydrostatic-pressure structures
• Effectiveness depends on a sound, well-graded mix and correct water-cement ratio; it cannot fix an inherently porous or badly compacted mix
• Does not bridge cracks or movement joints, which still need dedicated sealants or treatments
• Proper curing by ponding or curing compound is essential to realise the benefit
• Being a mix admixture, it does nothing for existing hardened concrete that is already leaking

Selection & best practice

Specifications

Industry use cases

How we position Sika SikaCim

SikaCim is the workhorse choice within Sika’s integral waterproofing range for everyday roof slabs and plaster. Where a job also needs a high-performance crystalline or advanced integral system, Sika’s own Sika WT and Sika-1 families step up. For surface leakage on existing terraces or wet areas, pair it with a Sika cementitious coating such as SikaTop Seal rather than relying on the admixture alone, and use a Sikaflex or Sika elastomeric sealant to treat cracks and joints, which an admixture cannot bridge. Across our other brands, comparable integral admixtures include Dr. Fixit LW+ and Fosroc’s Conplast waterproofing range, so specifiers standardising on a single supplier can be matched accordingly. Space Arc stocks the full Sika construction-chemicals line and can advise on the right combination for a given detail.

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